NO.sub.x gases are recognized to be a major source of air pollution in the United States and in all industrialized countries of the world. As a result, environmental emission standards are being imposed by various governmental authorities which limit the amount of NO.sub.x gases which can be emitted into the atmosphere. These standards have led to the development of various burners designed to inhibit the production of NO.sub.x gases or to consume furnace gases containing NO.sub.x gases. Such designs include burners which inject a jet of combustible gas or liquid axially into a flame through a center passage, and furnace gases or flue gases mixed with air are introduced through surrounding passages. Other designs include means for the introduction of a primary fuel axially into a burner combustion zone and steam radially into a burner combustion zone which, in turn, draws furnace gases into the burner combustion zone for consumption. Although various of these designs are advantageous, there is a need for burner designs having improved efficiency particularly in the ability of the burners to draw the furnace or flue gases into the combustion zone rapidly and in large quantities for mixing with fuel and combustion air, and consumption without the assistance of steam or other gases.